Safe and non-toxic hydroxyalkylation of xylan using propylene carbonate

Akil, Youssef; Lorenz, Dominic; Lehnen, Ralph; Saake, Bodo

doi:10.1016/j.eurpolymj.2016.02.010

Cited by 16 publications

(5 citation statements)

References 26 publications

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“…In addition to the common chemical modification methods mentioned above, other methods for the chemical modification of polysaccharides consist of carboxymethylating [ 54 ], benzoylating [ 55 ], alkylating [ 56 ], hydroxypropylating [ 57 ], etc. As is well established, the pharmacological activity of most compounds depends on their structure.…”

Section: Methods For the Chemical Modification Of Polysaccharidesmentioning

confidence: 99%

Chemical Modification of Polysaccharides: A Review of Synthetic Approaches, Biological Activity and the Structure–Activity Relationship

et al. 2023

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Natural polysaccharides are macromolecular substances with great potential owing to their wide biological activity and low toxicity. However, not all polysaccharides have significant pharmacodynamic activity; hence, appropriate chemical modification methods can be selected according to the unique structural characteristics of polysaccharides to assist in enhancing and promoting the presentation of their biological activities. This review summarizes research progress on modified polysaccharides, including common chemical modification methods, the change in biological activity following modification, and the factors affecting the biological activity of chemically modified polysaccharides. At the same time, the difficulties and challenges associated with the structural modification of natural polysaccharides are also outlined in this review. Thus, research on polysaccharide structure modification is critical for improving the development and utilization of sugar products.

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Section: Methods For the Chemical Modification Of Polysaccharidesmentioning

confidence: 99%

Chemical Modification of Polysaccharides: A Review of Synthetic Approaches, Biological Activity and the Structure–Activity Relationship

et al. 2023

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“…There are several cyclic carbonates commercially available in the market, including propylene carbonate (PC), ethylene carbonate (EC, glycerol carbonate (GC), and vinyl ethylene carbonate (VEC). Yet, PC and EC are the most commonly used as alkylating agents of phenols [ 60 ] and more recently in the oxypropylation of biomass [ 12 , 59 , 62 ]. This may be associated with the fact that, for instance, PC presents interesting features, such as low toxicity, high boiling point, low vapor pressure, and low inflammability ( Table 3 ), making it an interesting solvent and reagent that can be a substitute of PO for the oxypropylation of lignins.…”

Section: Synthesis Of Lignin-based Polyether Polyolsmentioning

confidence: 99%

“…Notice should be taken that attention is required when the reaction is carried out with lignin, as high temperatures in the alkaline medium may lead to structural changes in lignin [ 67 ]. Some studies have investigated the ring open polymerization of cyclic carbonates (especially propylene carbonate) using different raw materials as initiators and different catalysts [ 62 , 63 , 65 ]. For example, Kühnel et al [ 63 ] studied the influence of reaction parameters on the ensuing bio-based polyols in order to obtain information to control and optimize the oxyalkylation of organosolv lignin with PC.…”

Section: Synthesis Of Lignin-based Polyether Polyolsmentioning

confidence: 99%

“…Although the homopolymer is able to react with isocyanate to produce PUs, its proportion can affect the polyol quality and the yield of oxyalkylation reaction. The formation of homopolymer alongside oxyalkylation of biomass using cyclic carbonates has been mentioned in some works [ 62 , 64 , 74 ], and even crosslinking reactions have been reported involving chain coupling through transesterification reactions of biomass with cyclic carbonate [ 65 ], but this issue has not been discussed in depth. Usually, after the oxyalkylation, the product obtained is a mixture of oxyalkylated biomass, some unreacted cyclic carbonate, and perhaps homopolymer.…”

Section: Synthesis Of Lignin-based Polyether Polyolsmentioning

confidence: 99%

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Lignin as a Renewable Building Block for Sustainable Polyurethanes

et al. 2022

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Currently, the pulp and paper industry generates around 50–70 million tons of lignin annually, which is mainly burned for energy recovery. Lignin, being a natural aromatic polymer rich in functional hydroxyl groups, has been drawing the interest of academia and industry for its valorization, especially for the development of polymeric materials. Among the different types of polymers that can be derived from lignin, polyurethanes (PUs) are amid the most important ones, especially due to their wide range of applications. This review encompasses available technologies to isolate lignin from pulping processes, the main approaches to convert solid lignin into a liquid polyol to produce bio-based polyurethanes, the challenges involving its characterization, and the current technology assessment. Despite the fact that PUs derived from bio-based polyols, such as lignin, are important in contributing to the circular economy, the use of isocyanate is a major environmental hot spot. Therefore, the main strategies that have been used to replace isocyanates to produce non-isocyanate polyurethanes (NIPUs) derived from lignin are also discussed.

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“…By chemical modification, such as hydroxypropylation, of alkali extracted xylans, the water solubility can be recovered. Previous studies on hydroxypropylation of xylans, using either propylene oxide or propylene carbonate as reagents, have shown the potential of this chemically modified, thermoplastic material [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Size-exclusion chromatography of xylan derivatives—the critical evaluation of macromolecular data

et al. 2017

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Hydroxypropyl xylans with varying degrees of substitution were characterized by size-exclusion chromatography. Molar masses of the samples were determined using two approaches: by conventional calibration with molar mass standards and by a multi-detection method that utilizes the combination of static light scattering, viscometry, and differential refractive index detection. The molar mass results obtained by the multi-detection method were accurate, but required the determination of separate refractive index increments for each structurally different sample. The column calibration approach with standard pullulan samples gave biased results due to the differences in hydrodynamic volumes between pullulans and hydroxypropyl xylans with similar molar masses. The degree of hydroxypropylation affected the chain conformation and compactness of the polymer chains. Mark-Houwink parameters and persistence length values suggested that the hydroxypropyl substituents reduced the flexibility of the xylan chain and made the polymer chain more extended.

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Safe and non-toxic hydroxyalkylation of xylan using propylene carbonate

Cited by 16 publications

References 26 publications

Chemical Modification of Polysaccharides: A Review of Synthetic Approaches, Biological Activity and the Structure–Activity Relationship

Chemical Modification of Polysaccharides: A Review of Synthetic Approaches, Biological Activity and the Structure–Activity Relationship

Lignin as a Renewable Building Block for Sustainable Polyurethanes

Size-exclusion chromatography of xylan derivatives—the critical evaluation of macromolecular data

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